HP and congenital thrombotic thrombocytopenic purpura: The blood tests revealed acute renal failure (serum creatinine 6.14 mg/dl), microangiopathic hemolytic anemia (Hemoglobin 11.9 g/dL, undetectable serum haptoglobin, positive schizocytes 1.5%, elevated lactate deshydrogenase 2000 UI/L), without regeneration (reticulocytes 4.2 G/L) associated with a thrombocytopenia (platelets 16 G/L).